U.S. patent number 4,649,710 [Application Number 06/804,929] was granted by the patent office on 1987-03-17 for method of operating an air conditioner.
This patent grant is currently assigned to Trinity Industrial Corporation. Invention is credited to Hidemasa Inoue, Hisashi Taniguchi.
United States Patent |
4,649,710 |
Inoue , et al. |
March 17, 1987 |
Method of operating an air conditioner
Abstract
In a method of operating an air conditioner for supplying an air
from the air conditioner to the inside of a chamber, the
temperature of the air supplied to the inside of the chamber upon
starting the operation of the air conditioner is increased to an
aimed temperature while maintaining the supplied air temperature
higher than the temperature at the surfaces of the inner wall of
the chamber and/or the equipments installed therein but lower than
the temperature the dew point for which is lower than the surface
temperature, whereby the moistures contained in the air supplied
from the air conditioner is prevented from condensating to form
water droplets on the inner wall of the chamber and/or the
equipments installed therein. The inside of the chamber can be
controlled to an aimed air-conditioned state rapidly without
causing undesired dewing phenomenon even during winter or like
other cold conditions.
Inventors: |
Inoue; Hidemasa (Seto,
JP), Taniguchi; Hisashi (Toyota, JP) |
Assignee: |
Trinity Industrial Corporation
(Tokyo, JP)
|
Family
ID: |
17306548 |
Appl.
No.: |
06/804,929 |
Filed: |
December 5, 1985 |
Foreign Application Priority Data
|
|
|
|
|
Dec 7, 1984 [JP] |
|
|
59-257453 |
|
Current U.S.
Class: |
62/92; 62/223;
236/44C; 62/176.2; 62/271; 454/51; 165/223 |
Current CPC
Class: |
F24F
11/30 (20180101); F24F 2110/20 (20180101); F24F
2110/10 (20180101) |
Current International
Class: |
F24F
11/08 (20060101); F24F 11/00 (20060101); F25D
017/06 () |
Field of
Search: |
;62/92,271,223,176.2
;98/115.2 ;236/44R,44C ;165/21 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Capossela; Ronald C.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Claims
What is claimed is:
1. A method of operating an air conditioner for supplying air from
the air conditioner to the inside of a chamber, comprising the
steps of:
supplying air to the inside of the chamber;
calculating a temperature of dew point for a surface within said
chamber; and
increasing a temperature of the air supplied to the inside of the
chamber to an aimed temperature upon starting an operation of the
air conditioner, while maintaining said supplied air temperature:
(a) higher than a chamber temperature, which is a temperature at
one of: (1) the surfaces of the inner wall of the chamber and (2)
the equipment installed therein, (b) lower than said temperature of
dew point, and (c) so that said temperature of dew point is lower
than said chamber temperature, whereby the moisture contained in
the air supplied from the air conditioner is prevented from
condensating to form water droplets in said chamber.
2. A method as in claim 1 comprising the further steps of:
increasing the temperature of the air supplied to the inside of the
chamber upon starting the operation of the air conditioner to an
aimed temperature while maintaining the supplied air temperature
higher than the chamber temperature but lower than a temperature,
the dew point for which is lower than the surface temperature;
and
operating a humidity controller when the supplied air temperature
and the surface temperature become substantially identical with
each other to humidify the air supplied to the inside of the
chamber.
3. A method of operating an air conditioner for supplying air from
the air conditioner to the inside of a chamber, comprising the
steps of:
detecting a temperature and a moisture content of the air upon
initiating an operation of the air conditioner;
continuously calculating the dew point of the air as it is supplied
to the inside of the chamber;
detecting a change in a chamber temperature at surfaces of at least
one of an inner wall of the chamber and equipment installed in said
chamber; and
increasing the temperature inside said chamber to a predetermined
temperature while maintaining the temperature of said air supplied
from said air conditioner to the inside of said chamber such that a
dew point of the supplied air is lower than the chamber
temperature, while maintaining the temperature of the supplied air
to be higher than the chamber temperature, thereby preventing the
moisture contained in the air supplied from the air conditioner to
said chamber from forming water droplets by condensation at said
surfaces of at least one of the inner wall of the chamber and the
equipment installed in said chamber.
4. A method as in claim 3, comprising the further step of
moistening the air supplied to the inside of said chamber by
starting a humidifying operation of said air conditioner when the
temperature of said air becomes substantially equal to a
temperature at said surfaces.
5. A method of operating an air conditioner to condition the air in
a cooled area, comprising the steps of:
detecting a temperature and humidity of a surface within the cooled
area;
determining a range of temperatures of air to be supplied to said
areas which will not cause dew to be produced on at least one of
said surfaces; and
supplying air within said range of temperatures.
6. A method as in claim 5 wherein said determining step includes
the further steps of:
calculating a dew point temperature corresponding to a dew point of
said surface within said cooled area; and
determining a range of temperatures in which said dew point is
lower than said surface temperature and in which dewing will not
occur on said surface.
7. A method as in claim 6 wherein air is supplied at substantially
a highest possible temperature within said range.
8. An apparatus for operating an air conditioner to condition air
in a cooled area, comprising:
means for detecting a temperature and humidity of a surface within
the cooled area;
means for determining a range of temperatures of air to be supplied
to said areas which will not cause dew to be produced on one of
said surfaces; and
means for supplying air within said range of temperatures.
9. An apparatus as in claim 8 wherein said determining means
includes:
means for calculating a dew point temperature corresponding to a
dew point of said surface within said cooled area; and
means for determining a range of temperatures in which said dew
point is lower than said surface temperature and in which dewing
will not occur on said surface.
10. An apparatus as in claim 9 wherein air is supplied at
substantially a highest possible temperature within said range.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns a method of operating an air conditioner
and, more specifically, it relates to a method of operating an air
conditioner particularly upon starting the air conditioner in the
winter season or like other cold conditions.
2. Description of the Prior Art
During winter, the temperature inside a chamber, for example, of a
coating booth, computer room, clean room and various laboratories
to be supplied with conditioned air from an air conditioner is
often lowered to about 0.degree.-5.degree. C. before the operation
of the air conditioner is started. Accordingly, if the air
conditioner is started under such a relatively cold condition to
supply a conditioned air at a relatively high temperature as it is
into the chamber as described above, the conditioned air is cooled
suddenly when brought into contact with the surfaces of inner walls
of the chamber and equipment installed therein. In this case, a
so-called dewing phenomenon occurs, in which the moisture contained
in the air cause condensation to form water droplets on the
surfaces of the inner walls or the equipments.
FIG. 1 is a diagram for illustrating the generation of the dewing
phenomenon, in which a dry-bulb temperature (.degree.C.) is
indicated on the abscissa and the absolute humidity (g/kg') is
indicated on the ordinate.
It is assumed here, for example, that an air controlled to a
humidity at 80% (refer to curve (I)) which is ideal for a coating
booth or the like is supplied at a temperature of 20.degree. C.
(point A). Then, the dew point for the air is determined as a
crossing point B at about 16.degree. C. between the horizontal
extension from the condition point A and the saturation curve (II).
Accordingly, if the temperature at the inner wall of the coating
booth or the equipments such as a coating machine or a reciprocator
installed therein is lower than 16.degree. C., that is, the
temperature at the point B, the dewing phenomenon is resulted to
form water droplets on the surfaces thereof.
Accordingly, during winter where the temperature in the coating
booth is usually lowered to about 0.degree.-5.degree. C., if air
conditioned by the air conditioner to a relative humidity of about
80% by humidifying the atmospheric air is supplied, it frequently
causes the dewing phenomenon.
Even in a case where the atmospheric air, for example, at about 40%
relative humidity is supplied to the coating booth while being
conditioned only for the temperature under heating to 20.degree. C.
(that is, with no humidification) by using an air conditioner
equipped only with a temperature controller, the dew point for the
supplied air lies at the temperature on the point E where the
horizontal extension from the condition point D for the air
intersects the saturation curve, that is, at about 5.degree. C.
Also during winter dewing phenomenon tends to occur in the winter
season where the temperature inside of the coating booth is usually
lowered about to 0.degree.-5.degree. C.
If water droplets are once formed to the surfaces of the inner
walls or the coating machines or the likes in the coating booth,
dust tends to adhere and contaminate the surfaces and droplets
would fall to deposit on the coated films upon working the coating
equipments thereby resulting in defective coating. In addition,
when the droplets thus formed are evaporated, the humidity in the
chamber rises abruptly failing to attain moderate control by the
air conditioner for the temperature and the humidity in the
chamber.
Accordingly, upon starting the coating operation in the coating
booth, it is required to heat the inside of the chamber for a time
until a desired temperature is reached and a time for heating to
completely evaporate the water droplets deposited to form to the
inner wall of the booth or the equipments installed therein is also
required. Thus, the method for starting the air conditioner
involves an inconvenience that the air conditioner has to be
operated preliminarily for one hour or so before starting the
operation of the coating booth.
Furthermore, if water droplets are formed on the surfaces of the
coating equipments installed in the coating booth as described
above or the surfaces of various electronic equipments installed
within a computer chamber, rust or electric troubles may resulted
to this equipment.
Particularly, in the case of supplying an air at a relatively high
temperature and a high relative humidity controlled by an air
conditioner equipped with a temperature controller and a humidity
controller to the inside of the chamber, the dewing phenomenon
occurs most frequency always as described above thereby remarkably
causing troubles such as rusting or electrical failures to the
equipments.
OBJECT OF THE INVENTION
It is, accordingly, an object of this invention to provide a method
capable of preventing the deposition of water droplets, that is,
the dewing phenomenon caused by the condensation of moistures
contained in an air supplied from an air conditioner to the inside
of a chamber upon contact with the surfaces of the inner wall of
the chamber or the equipments installed therein when the operation
of the air conditioner is started in the winter season or like
other cold condition.
SUMMARY OF THE INVENTION
The foregoing object can be attained in accordance with this
invention, which comprises a method of operating an air conditioner
for supplying an air from the air conditioner to the inside of a
chamber, wherein the temperature of the air supplied to the inside
of the chamber upon starting the operation of the air conditioner
is increased to an aimed temperature while maintaining the supplied
air temperature higher than the temperature, at the surfaces of the
inner wall of the chamber and/or the equipments installed therein
but lower than the temperature the dew point for which is lower
than the surface temperature, whereby the moistures contained in
the air supplied from the air conditioner is prevented from
condensating to form water droplets on the inner wall of the
chamber and/or the equipments installed therein.
There is further provided a method of operating an air conditioner
equipped with a temperature controller and a humidity controller
for effecting the temperature and humidity control to supply a
controlled air from the air conditioner to the inside of a chamber,
wherein the temperature of the air supplied to the inside of the
chamber upon starting the operation of the air conditioner is
increased by the temperature controller to an aimed temperature
while maintaining the supplied air temperature higher than the
temperature, at the surfaces of the inner wall of the chamber
and/or the equipments installed therein but lower than the
temperature the dew point for which is lower than the surface
temperature, and, thereafter, the humidity controller is operated
when the supplied air temperature and the surface temperature
become substantially identical with each other to thereby humidify
the air supplied to the inside of the chamber, whereby the
moistures contained in the air supplied from the air conditioner is
prevented from condensating to form water droplets on the inner
wall of the chamber and/or the equipments installed therein upon
starting the operation of the air conditioner.
In accordance with the method of this invention, since the air
supplied to the inside of the chamber while being put under the
temperature control by a temperature controller disposed in the air
conditioner upon starting the operation thereof is maintained at a
temperature higher than the temperature at the surfaces of the
inner wall of the chamber or the equipments installed therein,
these inner walls and the equipments installed are gradually warmed
and the surface temperature thereof is gradually increased to a
aimed temperature together with the temperature for the supplied
air. In addition, since the temperature of the air is always
maintained lower than the temperature the dew point for which is
lower than the surface temperature as described above, the air upon
contact with the surfaces of the inner walls or the installed
equipments, is not cooled to lower than the dew point and,
accordingly, causes no dewing phenomenon.
Furthermore, in an air conditioner equipped both with a temperature
controller and a humidity controller, only the temperature control
is effected at first as described above and the humidification is
not effected while there is a difference between the temperature
for the supplied air and the surface temperature. Since the
humidification for the supplied air is started after the
temperature difference has substantially been eliminated, if the
relative humidity of the supplied air is increased by the start of
the humidification to raise the dew point thereof, no dewing
phenomenon occur.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
These and other objects, features, as well as advantageous effects
of this invention will now be described more in details referring
to the accompanying drawings, wherein:
FIG. 1 is a condition diagram for explanating the generation of the
dewing phenomenon;
FIG. 2 is a view showing the entire structure of an air conditioner
for explanating the method according to this invention;
FIG. 3 is an explanatory view for the control device thereof;
FIG. 4 is a flow chart showing the procedures for the processing
steps effected by the control device;
FIG. 5 is a condition diagram for explanating the control of the
supplied air temperature according to the method of this
invention;
FIG. 6 is a view for the entire structure of the air conditioner
for explanating the method of this invention; and
FIG. 7 is a graph showing the time-dependent controlled state for
the surface temperature of the inner wall of the chamber and the
equipments installed therein and the supplied air temperature
according to this method.
DESCRIPTION OF PREFERRED EMBODIMENTS
This invention is to be described while referring to preferred
embodiments.
EXAMPLE I
FIG. 2 is an explantory view showing one example of an air
conditioner used in the method of this invention.
An air conditioner 1 is adapted to eliminate dust contained in the
atmospheric air introduced through a gallery 2 by way of a saran
net 3 and a roll filter 4, conduct temperature control by heating
the cleaned air to an aimed temperature by a temperature controller
5, and then supply the heated air by a blower 6 through an air
supply duct 7 to the inside of a coating booth 8 for use in a
vehicle coating.
The temperature controller 5 uses, for example, a fin heater of a
type that heats air through heat-exchange between an air stream and
of warmed water, in which the warmed water is kept under a
superatmospheric pressure in a sealed closed expansion tank (not
illustrated), so that high temperature water heated to
100.degree.-160.degree. C. is supplied by an introducing pipe 9 and
then recycled through a return pipe 10.
A flow rate control valve 11 is inserted at the midway of the
introducing pipe 9 and the opening degree of the control valve 11
is adjusted by a control signal CM from a control device 12.
As shown in FIG. 2, the control device 12 is constituted with a
microcomputer comprising, for example, an interface circuit 13, a
processing device 14 and a memory device 15.
A temperature detector 16 and a humidity detector 17 for detecting
the temperature and the humidity of the air supplied from the air
conditioner 1, as well as a temperature detector 18 for detecting
the temperature at surfaces of the the inner wall of the coating
booth 8 and the equipments installed therein are disposed on the
inside of the coating booth 8 and connected respectively by way of
A/D converters 19, 20 and 21 to the input of the interface circuit
13. The control valve 11 is connected directly to the output of the
interface circuit 13.
The processing device 14 performs predetermined processing upon
reading the detected data ET, EW and KT from the temperature
detector 16, the humidity detector 17 and the temperature detector
18 and outputs the control signal CM for adjusting the opening
degree of the control valve 11.
The memory device 15 stores a program for executing the processings
in the processing device 14 and also stores the data for the dew
point at any of condition points determined by the dry-bulb
temperature and the relative humidity, as well as an aimed set
temperature RT (for example, at 20.degree. C.).
The procedures for the processing performed by the processing
device 14 will now be explained in accordance with the flow chart
shown in FIG. 4.
FIG. 4 shows the processing steps for controlling the temperature
of the supplied air upon starting the operation of the air
conditioner 1. At first in the step (1), upon starting the
operation of the air conditioner 1, the temperature detection data
ET from the temperature detector 16, the humidity detection data EW
from the humidity detector 17 and the temperature detection data KT
from the temperature detector 18 are read and the respective data
are temporarily stored to predetermined memory areas in the memory
device 15.
Then, the program processes to the step (2), where the respective
data stored in the step (1) are read out and the highest supplied
air temperature ST that can heat the inside of the coating booth 8
without resulting dew on the surfaces of the inner wall of the
coating booth 8 and the equipments installed therein is calculated
with reference to the dew point Xt for the condition point
determined by the dry-bulb temperature and the relative humidity
stored in the memory device 15.
That is, the supplied air temperature ST is calculated as a
temperature, which temperature is higher than the surface
temperature KT on the inner wall of the coating chamber and the
equipments installed therein, but which is lower than a condition
point the dew point Xt for which in connection with the relative
humidity EW is lower than the surface temperature. The temperature
ST is desirably as high as possible within the range determined by
the dew point Xt.
Then, the supplied air temperature ST is temporarily stored in a
predetermined memory area in the memory device 15.
Then, the program is proceeds to the step (3), where the supplied
air temperature ST stored in the step (2) is read out and compared
with a desired setting temperature RT stored in the memory device
15 (for example, 20.degree. C.) to judge whether the value for the
supplied air temperature ST is lower than the value for the setting
temperature RT or not.
If ST is lower than RT (ST<RT), the program is proceeded to the
step (4), where a proportional control operation amount Yi (=Kp
(ST-ET)), in which Kp represents a conversion constant, is
calculated based on the supplied air temperature ST and the
temperature detection data ET stored in the predetermined memory
area of the memory device 15. Then, the program proceeds to step
(5), where a control signal CM, corresponding to the operation
amount Yi, is outputted by way of the interface circuit 13 to the
control valve 11 and then the flow is returned to the step (1).
In the case where the the supplied air temperature ST is higher
than the setting temperature RT(ST.gtoreq.RT), the program proceeds
to the step (6) to judge whether the temperature detection data ET
is equal to the setting temperature data RT. If the temperature
detection data ET is lower than the setting temperature RT
(ET<RT), the program proceeds to the step (7), where a
proportional control operation amount Yii (=Kp (RT-ET)) is
calculated, which is stored in the predetermined memory area in the
memory device 15. Then, the program is proceeded to the step (5),
where the control signal CM corresponding to the operation amount
Yii is outputted by way of the interface circuit 13 to the control
valve 11 Thereafter, the program returns to the step (1). If ET=RT
at the step 6, the processing is ended.
The constitution of the air conditioner 1 and the control device 12
used in the method of this invention are as described above and the
execution of the method according to this invention will now be
explained next referring to FIG. 5.
In a case where the temperature in the coating booth 8 is lowered
to 5.degree. C. and the relative humidity is at 70%, for instance,
if air is supplied directly at the air supply temperature of
15.degree. C.-20.degree. C. from the air conditioner 1 to the
inside of the coating booth 8, since the dew point for the air
ranges about from 8.degree. C. to 14.degree. C., the air is cooled
within the coating booth to lower than the dew point to result in
dewing phenomenon, and the moistures in the air will fall like a
mist and form water droplets on the surfaces of the inner wall of
the booth and the equipments installed therein. However, if the
temperature for the supplied air is controlled to lower than
10.degree. C., no dewing phenomenon is resulted even if the air in
the coating booth is cooled down to 5.degree. C. since the dew
point in this case is lower than 5.degree. C.
Upon starting the operation of the air conditioner 1 in the winter
season, the respective detection data from the temperature detector
16, the humidity detector 17 and the temperature detector 18 in the
coating booth 8 are inputted to the control device 12 and the
processing device 14 sequentially calculates, based on the detected
data, the highest temperature from the temperature range of the
detected data from the temperature detector 18 that detects the
surface temperature at the inner wall or the equipments, but within
a range of temperature as not causing the dewing phenomenon.
Then, a control signal CM is outputted with a proportional control
operation amount depending on the calculated supplied air
temperature to the control valve 11 that supplies water at high
temperature to the temperature controller 5 in the air conditioner
1, thereby increasing the supplied air temperature to an aimed set
temperature while adjusting the opening degree of the control valve
11.
As described above according to the method of this invention, upon
starting the operation of the air conditioner 1, since the supplied
air temperature of the air supplied to the inside of the chamber
such as of the coating booth 8 is maintained to such a temperature
as not causing dewing even if the air is cooled in contact with the
inner wall and the equipments in the chamber, it can provide an
advantageous effect of minimizing rusting and electrical troubles
to the equipment as experienced so far in the prior art.
Further, since the evaporation of water droplets formed at the
surfaces of the inner wall or the equipments as in the prior art is
no more necessary, the time required for the preliminary operation
can significantly be shortened to remarkably improve the working
efficiency.
Moreover, the preliminary operation time can further be shortened
by increasing the temperature of the air supplied from the air
conditioner 1 to the inside of the coating booth 8 or the like in a
state while always maintaining the supplied air temperature at the
highest value within the range of temperature not causing the
dewing phenomenon.
EXAMPLE II
FIG. 5 is an explanatory view showing an embodiment of an air
conditioner adapted to perform control both for the temperature and
the humidity control, in which the air conditioner 1 is so adapted
that atmospheric air introduced through a gallery 2 is eliminated
with dusts by way of a saran net and a roll filter 4 and the
cleaned air is applied with preliminary heating by a temperature
controller 5a called as a pre-heater and, further, humidified
through a humidity controller 20 comprising a shower type
humidifier or the like and then subjected to temperature and
humidity control by a temperature controller 5b called as a
pre-heater, which is supplied by a blower 6 to the inside of the
coating booth 8.
Flow rate control valves 11a and 11b are inserted respectively at
the midway of introducing pipes 9a and 9b for supplying water at
high temperature to the temperature controllers 5a and 5b and the
opening degree for the control valves 11a, 11b are adjusted by a
control signal CM from a control device 12.
A flow rate control valve 22 is disposed at the midway of a pipeway
21 supplying warmed water for humidification to a humidifier 20 and
the control valve 22 is ON-OFF controlled by a control signal CP
from the control device 12.
Since other constitutions are identical with those in the foregoing
embodiment, detailed explanations therefor are omitted.
In this embodiment, detection data are inputted from a temperature
detector 16, a humidity detector 17 and a temperature detector 18
disposed in a coating booth 8 respectively to the control device
12. Then, based on the detection data, a processing device 14
sequentially calculates the supplied air temperature as a
temperature lower than that causing the dewing phenomenon and
higher than any of the values of the detection data from the
temperature detector 18 for detecting the surface temperature of
the inner wall and the equipments.
Then, the control signal CM is outputted with a proportional
control operation amount depending on the calculated supplied air
temperature, to each of the control valves 11a, 11b for supplying
water at high temperature to the temperature controllers 5a, 5b in
the air conditioner 1 and the supplied air temperature is increased
to an aimed temperature while adjusting the opening degree of the
control valves 11a, 11b.
Then, at the instance where the supplied air temperature and the
value of the detection data from the temperature detector 18 are
substantially identical with each other (point F shown in FIG. 7),
a control signal CP is outputted from the control device 12 to the
control valve 22 inserted to the pipeway 21 for supplying warmed
water to the humidity controller 20, to actuate the humidity
controller thereby start the humidification.
Thus, the relative humidity of the air supplied from the air
conditioner 1 to the inside of the coating booth 8 is increased
and, accompanying therewith, the dew point therefor is raised.
However, since the temperature for the air and the surface
temperature at the inner wall in the coating booth 8 and the
equipments installed therein are substantially identical with each
other, there is no risk that the air is cooled down below the dew
point upon contact with the inner wall and the installed equipments
and, accordingly, no dewing phenomenon is resulted.
In the method as described above of this invention, since only the
temperature controllers 5a, 5b are actuated at first at the start
of the operation for the air conditioner 1 and the temperature for
the air supplied to the inside of the coating booth 8 or the like
is increased in a state while maintained to such a temperature as
causing no dewing even if the air is cooled by being contact with
the inner wall and the equipments in the chamber and, thereafter,
the humidifier 20 is actuated to perform humidification when the
supplied air temperature and the surface temperature of the inner
wall and the equipments are substantially identical with each
other, no dewing phenomenon is resulted to the surfaces of the
inner wall in the chamber and the equipments installed therein upon
starting the operation of the air conditioner 1 and the inside of
the chamber can rapidly be controlled for the temperature and the
humidity during winter.
As described above, according to the method of this invention,
since the air supplied to the inside of the chamber while being
under temperature control by the temperature controller disposed in
the air conditioner upon starting the operation of the device is
maintained at a temperature higher than the temperature at the
surfaces of the inner wall in the chamber or the equipments
installed therein, the inner wall and the equipments are gradually
heated thereby gradually increasing the surface temperature
thereof. At the same time, since the air is maintained at such a
temperature as the dew point therefor is lower than the surface
temperature, the air is not cooled below the dew point and the
dewing phenomenon is not caused even the air is in contact with the
surfaces of the inner walls or the equipments. Accordingly, it has
an excellent effect capable of preventing the troubles such as
contamination to the inner wall in the chamber, or generation of
rusts or electrical failures to the equipments. Further, it can
also provide an advantageous effect that no preliminary operation
so far required for evaporating the once condensated moistures is
no more necessary and the working efficiency can be improved
significantly.
Particularly, in an air conditioner equipped both with the
temperature controller and the humidity controller, since only the
temperature control is effected at first as described above, while
the humidity control is not effected so long as there is a
difference between the temperature of the supplied air and the
surface temperature but the humidity control is effected at the
instance that the temperature difference is substantially
eliminated, it has an excellent effect of causing no dewing
phenomenon when if an air humidified to a relatively high humidity
is supplied to the chamber.
* * * * *